Improvement in indicator-locks



3 Sheets-S'het 1. L. R. NORMAN. INDICATOR LOCK.

Patented Dec. 7, 1875-.

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"PETERS, FHOTO-UTKOGRAPHER, WASNINGTON, D C.

3 Sheets-Sheet 2.

L. R. NORMAN.

INDICATOR LOCK.

Patented Dec. 7, 1875.

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mvcmom NJETERS, FHOI'O-UTHDGRAPHER. WASHINGTONv D. C.

3 Sheets-sheaf, a

L. R. NORMAN.

INDICATOR LOCK.

Patented Dec. 7, 1875.

ATTE ST:

W W M Unrrn STATES PATENT OFFIon.

LESLIE R. NORMAN, OF ST. LOUIS, MISSOURI.

IMPROVEMENT IN INDICATOR-LOCKS.

Specification forming part of Letters Patent No. 170,889, dated December7, 1875; application filed October 8, 1875.

To all whom it may concern:

Be it known that l, LESLIE R. NORMAN, of the city and county of St.Louis and State of Missouri, have invented a new and useful ImprovedLock, which improvement is fully set forth in the followingspecification, reference being bad to the accompanying drawings.

My invention consists in providing the bolt with a spring-pawl, whichengages and operates a ratchet-wheel of an indicator or register at eachmovement of the bolt, and thus indicates the number of times the bolthas been moved. y

In the accompanying drawings, Figure 1 is a perspective view of thelock. Fig. 2 is a side elevation of the lock mechanism, the front plateof the casin g being removed. Fig. 3 is a rear view of the front plateof the easing. Fig. 4 is an under perspective of the lock-bolt. Fig. 5is an under perspective of the tumbler and casing. Fig. 6 is a side viewof the same. Fig. 7 is a side view of the key. Fig. 8 is a perspectiveview of the plate coverin g the dials.

A is the casing of the lock, of any suitable form and construction,having a front plate, B, which is provided with a housing, 0, for thereception of a rotatable disk, D, which has notches d in its periphery,in which engages a springpawl, (1 so arranged that the disk can berotated in one direction only. This disk has a central opening, (1through it for the reception of the stem of the key E, and on each sideof this opening are radial slots d for the reception of the lugs c e ofthe key. Back of this disk is the tumbler-casing F, having openings fimmediately beneath the opening 61 and said opening has radial slots fsimilar to d for the passage of the lugs e e of the key. This casing Fis composed of three or more plates of steel, between which plates arearranged the tumblers G, which have the usual tumbler-lugs g, which playin the tumbler-slots h of the bolt H. The tumblers are held down bysprings 9 said slots h having the usual false wards h ,-in which thetumblers engage to prevent the bolt being operated when an attempt ismadeto open the look by a false or blank key. I is a spring-pawl,pivoted to the lockbolt H, and engaging and operating the ratchet-wheelj of the first dial-plate J. In the drawings this dial-plate is shownwith a projectiug tooth, j, which, on each rotation of the dial J, movesthe dial K around one tooth ot' the ratchet-wheel 7c of said dial K.Similarly the dial L is operated by the tooth k engaging theratchet-wheel l of the dial L. M i are springdogs to prevent thebackward movement of the dials. These disks constitute a registeringmechanism for indicating the number of times the lock has been opened,and a more or less number of disks may be used to form the indicator,according to the number of times the indicator is required to indicate.In front of these disks is a sunken plate or cover, M, to the dials, andhaving openings m through it for the purpose oi'showing the number thatthe dials indicate. These openings are covered bya hinged lid, N, whichmay be provided with a lock if desired. 0 is a pivoted spring-lever,which, when the indicator has reached its last indication, said leversprings into a notch, h in the lock-bolt H and into the notch l of thelast one of the dials, and locks the indicating mechanism and thelock-bolt, so as to prevent their further action by the key. 1

In the construction shown by the drawings this locking of the bolt andindicating mechanism takes place when the lock is open. By changing theposition of the notch k this locking of the bolt, 860., may be made totake place when the lock is locked. In the drawings my improvements areshown as applied to a padlock; but it is equally applicable to door orother locks, the only change required being that the bolt H be made toplay through the casing A in the ordinary manner.

The operation of my improvement is as follows: The key is firstintroduced into the slots 0? d of the disk D, and turned a quarterround, which brings it over one of the slots f into which the key ispushed, so as to bring the lug e in line with the tumblers. It is thenturned forward, and in turning the lug e lifts the tumblers, and the luge moves the bolt. In case a blank or false key should be used it wouldbe caught in the look, so that it could not be withdrawn, as thetumblers would prevent its being turned forward, and

the spring-pawl d and disk D would prevent I its being turned backward;and therefore it would remain fixed in the lock. On each backwardmovement or unlocking of the bolt the spring-pawl I turns the disk J onenotch of the ratchet j, and this dial J at every rotation moves the dialK one notch of the ratchet 7c. Similarly each rotation of the dialKmoves the dial L one notch of the ratchet l, and when said dial L hasreached its last indication a spring-lever, 0, drops into a notch, 1 inits periphery and into a notch, h of the bolt and locks them both, sothat no further movement can be communicated to them.

I claim as my invention-- 1. The lock-bolt H, having spring-pawl I,

in combination with the dials. J K L, and

LESLIE R. NORMAN.

Witnesses ROBERT BURNS, JOHN WINTER.

